Washing machine with detection device

ABSTRACT

A washing machine including a combined detecting device adapted to detect both a water level and vibration of the washing machine. The washing machine includes a water tub adapted to contain wash water, a washing device adapted to wash laundry contained in the water tub, and a combined detecting device which detects both a water level and vibration of the water tub. The combined detecting device includes a case coupled to the water tub and having an inlet for use in the passage of air, a pressure pipe connected between a lower portion of the water tub and the inlet of the case, a pressure sensor which detects pressure variation in the case, and a vibrator member reciprocably installed in the case and which induces the pressure variation in the case during generation of the vibration.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.2004-36204, filed on May 21, 2004 in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

An apparatus consistent with the present invention relates to a washingmachine and, more particularly, to a washing machine comprising acombined detecting device capable of detecting not only a water level,but also a vibration in the washing machine.

2. Description of the Related Art

In general, a washing machine comprises a water level sensor adapted todetect the level of wash water supplied in a water tub during wash andrinse cycles, and a vibration sensor adapted to detect a vibration ofthe water tub generated during a high-speed spin-dry cycle. Such a waterlevel sensor enables the control of water supply operation of thewashing machine according to the detected water level in the water tub,and the vibration sensor permits the control of operation in such afashion that the washing machine is stopped at the time the vibrationsensor detects excessive vibration generated in the washing machine. Insuch a conventional washing machine, however, since the water levelsensor and the vibration sensor are provided as individual parts, andthus are mounted at separate positions in the washing machine, thenumber of overall parts of the washing machine increases, and the numberof manufacturing steps also increases, resulting in a deterioration inprice competitiveness.

In order to solve the above problem, recently, a sensor, adapted todetect not only a water level, but also a vibration in a washingmachine, has been developed in the related fields. One example of such asensor is disclosed in Korean Patent No. 10-338262 (published on May 27,2002). The disclosed sensor for detecting both a water level and avibration of a washing machine, comprises, water level detectingelements of a diaphragm, a core, a case, and a coil. The diaphragm isdeformable by variation of a pneumatic pressure depending on the waterlevel in the washing machine, and the core is displaceable according tovariation in the shape of the diaphragm. The case is configured toenclose the diaphragm and a core holder, and the coil is installed inthe case to surround the core such that it can detect the displacementof the core. In such a conventional sensor configured as stated above,when the diaphragm is deformed according to the variation of the waterlevel, the core is displaced inside the coil, thereby enabling detectionof the water level through inductance variation.

Further, the disclosed sensor includes vibration detecting elementscomprising a vibration detector which defines a predetermined space inone side of the coil and has an inclined surface, and a rolling membermovably installed in the vibration detector. When vibration is generatedin the washing machine, the rolling member installed in the vibrationdetector is moved along the inclined surface of the vibration detectorto cause inductance variation in the coil, thereby enabling detection ofthe vibration.

In the case of the above described sensor, although it takes the form ofa single unit capable of detecting both the water level and vibration ofthe washing machine, it comprises the diaphragm, core, coil, etc., aselements used only to detect the water level, and the vibration detectorhaving the inclined surface and the rolling member, as elements usedonly to detect the vibration, resulting in an increase in the number ofoverall elements, and a complicated structure. Such a conventionalsensor is difficult to manufacture, and exhibits high manufacturingcosts. Further, in principle, the sensor can detect the vibration of thewashing machine only through movement of the rolling member induced whenthe vibration is generated, and this makes it difficult to detect thepresence and magnitude of fine vibrations.

SUMMARY OF THE INVENTION

Illustrative, non-limiting embodiments of the present invention overcomethe above disadvantages and other disadvantages not described above.Also, the present invention is not required to overcome thedisadvantages described above, and an illustrative, non-limitingembodiment of the present invention may not overcome any of the problemsdescribed above.

The present invention has been made in view of the above mentionedproblems, and an aspect of the invention is to provide a washing machinecomprising a combined detecting device, which can detect both a waterlevel and a vibration of the washing machine, and exhibit easymanufacture and competitive manufacturing costs by virtue of asimplified structure thereof.

Another aspect of the invention is to provide a washing machinecomprising a combined detecting device capable of accurately detectingthe presence and magnitude of fine vibrations.

An apparatus consistent with an aspect of the present invention providesa washing machine comprising a water tub adapted to contain wash water,a washing device adapted to wash laundry contained in the water tub, anda combined detecting device which detects both a water level andvibration of the water tub, the combined detecting device comprising: acase coupled to the water tub and having an inlet for use in the passageof air; a pressure pipe connected between a lower portion of the watertub and the inlet of the case; a pressure sensor which detects pressurevariation in the case; and a vibrator member reciprocably installed inthe case and which induces the pressure variation in the case duringgeneration of the vibration.

The pressure sensor may be installed at an opposite side of the inlet ofthe case.

The vibrator member may include: a flexible connector member whichconnects an outer periphery of the vibrator member to an innerperipheral surface of the case in a substantially air-tight manner, andto permit reciprocation of the vibrator member; and a through-holeperforated through the vibrator member.

The vibrator member may be installed in the case between the inlet ofthe case and the pressure sensor.

The combined detecting device further comprises: an outlet formed at thecase at an opposite side of the inlet; and a connection pipe connectedbetween the outlet and the pressure sensor and which allows the pressuresensor to detect the pressure variation transmitted through the outlet.

The pressure sensor may be a piezoelectric element.

The combined detecting device may further comprise an amplificationcircuit which amplifies an electric signals outputted from the pressuresensor.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more easily appreciated from the following description ofthe exemplary embodiments, taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a sectional view illustrating a washing machine in accordancewith a first exemplary embodiment;

FIG. 2 a sectional view illustrating a combined detecting device for usein the washing machine in accordance with the first exemplaryembodiment;

FIG. 3 is a graph illustrating pressure variation of the combineddetecting device depending on vibration generated in the washingmachine;

FIG. 4 is a graph illustrating pressure variation of the combineddetecting device depending on the rising of a water level in the washingmachine;

FIG. 5 is a sectional view illustrating a second exemplary embodiment ofthe combined detecting device of the washing machine; and

FIG. 6 is a sectional view illustrating an example wherein an exemplaryembodiment of the combined detecting device is applied to a drum-typewashing machine.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE, NON-LIMITING EMBODIMENTS OFTHE PRESENT INVENTION

Reference will now be made in detail to illustrative, non-limitingembodiments of the present invention, examples of which are illustratedin the accompanying drawings, wherein like reference numerals refer tothe like elements throughout. The exemplary embodiments described belowexplain the present invention by referring to the figures.

Referring to FIG. 1, the washing machine of a first exemplary embodimentcomprises a water tub 11 installed in a body case 10 and adapted tocontain wash water, and a washing tub 12 rotatably installed in thewater tub 11. The water tub 11 is supported at a lower exterior sidethereof by means of suspension devices 13. The washing machine furthercomprises a water supply device 14 having a water supply pipe 14 a and awater supply valve 14 b mounted at an upper portion of the water tub 11for supplying the wash water into the water tub 11, and a drainagedevice 15 having a drainage pipe 15 a and a drainage valve 15 b mountedat a lower portion of the water tub 11 for discharging the wash waterreceived in the water tub 11 to the outside.

Inside the washing tub 12 is installed a pulsator 16, which is rotatableforward or reverse to produce wash water streams. In order to rotateboth the washing tub 12 and the pulsator 16, below the water tub 11 isprovided a driving device. Such a driving device comprises a drivingmotor 17 for generating rotation power upon receiving a power-supplyvoltage, a power transmission mechanism 18 for selectively transmittingthe rotation power of the driving motor 17 to one or both of thepulsator 16 and the washing tub 12, and a belt 19 used as a powertransmission medium connected between the driving motor 17 and the powertransmission mechanism 18.

The washing machine of the first exemplary embodiment further comprisesa combined detecting device 20 which is adapted to detect a water levelin the water tub 11 in order to keep the water level at an appropriatevalue conforming to the amount of laundry contained in the washing tub12 during a wash cycle, and to detect a vibration of the water tub 11.

Referring to FIGS. 1 and 2, the combined detecting device 20 comprises acase 21 mounted at an upper exterior side of the water tub 11, the case21 internally defining a pressure space 22 and having an inlet 21 a andan outlet 21 b formed at opposite sides of the case 21, and a pressurepipe 23 connected between a lower portion of the water tub 11 and theinlet 21 a of the case 21. A lower end of the pressure pipe 23 isconnected to the lower portion of the water tub 11 such that itcommunicates with the interior of the water tub 11 for allowing the washwater filled in the water tub 11 to be introduced into the pressure pipe23. With such a configuration, as the interior space of the water tub 11is filled with the wash water, a water level inside the pressure pipe 23is correspondingly raised, causing an internal pneumatic pressure of thepressure pipe 23 to increase. Such an increased pneumatic pressure ofthe pressure pipe 23 can be transmitted to the pressure space 22 of thecase 21.

The combined detecting device 20 further comprises a sensor case 25connected to the outlet 21 b of the case 21 by means of a connectionpipe 24, and a pressure sensor 26 installed in the sensor case 25. Insuch a configuration, as an internal pressure of the case 21 istransmitted to the sensor case 25 through the connection pipe 24, thepressure sensor 26 can detect variation in the water level of the watertub 11 from the transmitted pressure. The pressure sensor 26 ispreferably, but not necessarily, a conventional piezoelectric elementadapted to convert pressure variation into electric signals, such that acontrol unit 100 of the washing machine can recognize a detectedpressure from the electric signals. The electric signals outputted fromthe pressure sensor 26 are amplified through an amplification circuit40, and then is transmitted to the control unit 100.

In addition to the detection of the pressure variation of the case 21according to the variation of the water level in the water tub 11, thecombined detecting device 20 can detect a vibration transmitted from thewater tub 11 to the case 21. For this, the combined detecting device 20further comprises a vibrator member 27, which is reciprocably installedin the pressure space 22 of the case 21. The vibrator member 27 may havea prescribed weight, and can take the form of a disk having an outerdiameter smaller than an inner diameter of the case 21. The vibratormember 27 is supported in the case 21 using a connector member 28. Theconnector member 28 is flexibly deformable to such an extent that itconnects an outer periphery of the vibrator member 27 to an innerperipheral surface of the case 21 in an air-tight manner, and that itpermits reciprocating movements of the vibrator member 27. The vibratormember 27 is centrally perforated with a through-hole 29 for allowingthe internal pressure of the case 21, generated by the variation of thewater level in the water tub 11, to be transmitted to the pressuresensor 26. In this case, the vibrator member 27 is preferably, but notnecessarily, made of rubber or resin having a prescribed thickness, andthe connector member 28 is preferably, but not necessarily, made of athin rubber film exhibiting a good flexibility.

In the combined detecting device 22 configured as stated above, when thecase 21 shakes due to the vibration of the water tub 11, the vibratormember 27 installed inside the case 21 reciprocates, causing thepressure variation in the pressure space 22 of the case 21. Thereby, thepressure sensor 26 detects such a pressure variance, thereby detectingthe vibration of the water tub 11. That is, since the amplitude andvibration frequency of the vibrator member 27 is proportional to thevibration of the water tub 11, and the pressure variance in the case 21is proportional to the amplitude and vibration frequency of the vibratormember 27, the pressure sensor 26 detects the pressure variance insidethe case 21, thereby being capable of detecting the vibration of thewater tub 11. During generation of the vibration, the pressure varianceinside the case 21 exhibits a feature as shown in FIG. 3. That is,during generation of the vibration, the pressure variance inside thecase 21 according to reciprocation of the vibrator member 27 increases,resulting in excessive change of the electric signals outputted from thepressure sensor 26. This enables the pressure sensor 26 to accuratelydetect the presence and magnitude of the vibration. In addition, theelectric signals outputted from the pressure sensor 26 are transmittedto the control unit 100 of the washing machine after being amplified bythe amplification circuit 40, enabling more accurate detection of thevibration.

Further, in the combined detecting device 20 the center through-hole 29of the vibrator member 27 allows the interior spaces of the case 21divided by the vibrator member 27 to communicate with each other. Thus,the internal pressure of the case 21, which is variable according to thewater level in the water tub 11, is transmitted to the pressure sensor26 through the through-hole 29, such that the pressure sensor 26 candetect the water level in the water tub 11. In the procedure ofdetecting the water level, as shown in FIG. 4, the internal pressure ofthe case 21 is raised in proportion to the rising of the water level,and the electric signals outputted from the pressure sensor 26 areproportionally raised, enabling detection of the water level.

FIG. 5 illustrates a second exemplary embodiment of the combineddetecting device of the washing machine. Different from the aboveexemplary embodiment, a combined detecting device 30 of the presentexemplary embodiment comprises a pressure sensor 32 adapted to detect aninternal pressure of a case 31. The pressure sensor 32 is installed inthe case 31 at a position opposite to an inlet 31 a of the case 31. Theconfiguration of a vibrator member 33 and a pressure pipe 34, as well asa principle for detecting both the water level and the vibration of thewashing machine are the same as the above embodiment, thus a descriptionthereof will be omitted.

FIG. 6 illustrates an example wherein an exemplary embodiment of thecombined detecting device according to the present invention is appliedin a conventional drum-type washing machine. In this case, the combineddetecting device, which is designated as reference numeral 40, comprisesa case 41 installed on a drum-type water tub 52, and a sensor case 43fixed to an inner top surface of a body case 51 of the drum-type washingmachine and having a pressure sensor 42. A pressure pipe 44 is connectedbetween a bottom of the drum-type water tub 52 and the case 41 installedon the drum-type water tub 52 such that a lower end of the pressure pipe44 communicates with the interior of the drum-type water tub 52, and anupper end thereof communicates with the interior of the case 41. Otherconfigurations and a principle of detecting both the vibration and thewater level of the washing machine are the same as the aboveembodiments, and thus will be omitted hereinafter.

As is apparent from the above description, a washing machine accordingto the present invention comprises a combined detecting device capableof detecting both a water level and a vibration of the washing machine,which features a simplified structure compared to the prior art, therebybeing easily manufactured and installed to the washing machine, andachieving a reduction in manufacturing costs thereof.

Further, in the combined detecting device of the washing machineaccording to the present invention, a pressure sensor can detect thewater level by detecting pressure variation inside a case transmittedthrough a through-hole of a vibrator member, and also can detect thevibration by detecting the pressure variation caused by reciprocation ofthe vibrator member, thereby enabling accurate detection of the presenceand magnitude of fine vibrations.

Although exemplary embodiments of the present invention have been shownand described, it will be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A washing machine comprising a water tub adapted to contain washwater, a washing device adapted to wash laundry contained in the watertub, and a combined detecting device which detects both a water leveland vibration of the water tub, the combined detecting devicecomprising: a case coupled to the water tub and having an inlet for usein the passage of air; a pressure pipe connected between a lower portionof the water tub and the inlet of the case; a pressure sensor whichdetects pressure variation in the case; and a vibrator memberreciprocably installed in the case and which induces the pressurevariation in the case during generation of the vibration.
 2. The washingmachine according to claim 1, wherein the pressure sensor is installedat an opposite side of the inlet of the case.
 3. The washing machineaccording to claim 2, wherein the vibrator member includes: a flexibleconnector member which connects an outer periphery of the vibratormember to an inner peripheral surface of the case in a substantiallyair-tight manner, and to permit reciprocation of the vibrator member;and a through-hole perforated through the vibrator member.
 4. Thewashing machine according to claim 3, wherein the vibrator member isinstalled in the case between the inlet of the case and the pressuresensor.
 5. The washing machine according to claim 1, wherein thecombined detecting device further comprises: an outlet formed at thecase at an opposite side of the inlet; and a connection pipe connectedbetween the outlet and the pressure sensor and which allows the pressuresensor to detect the pressure variation transmitted through the outlet.6. The washing machine according to claim 5, wherein the vibrator memberincludes: a flexible connector member which connects an outer peripheryof the vibrator member to an inner peripheral surface of the case in asubstantially air-tight manner, and to permit reciprocation of thevibrator member; and a through-hole perforated through the vibratormember.
 7. The washing machine according to claim 6, wherein thevibrator member is installed in the case between the inlet and theoutlet.
 8. The washing machine according to claim 1, wherein thepressure sensor comprises a piezoelectric element.
 9. The washingmachine according to claim 1, wherein the combined detecting devicefurther comprises an amplification circuit which amplifies a electricsignals outputted from the pressure sensor.